United Nations Under-Secretary-General for Humanitarian Affairs and Emergency Relief Coordinator Valerie Amos is seen in a car as she leaves a hotel in Damascus January 12, 2014. REUTERS/Khaled al-Hariri

DAMASCUS (Reuters) - United Nations aid chief Valerie Amos said on Sunday the world body hoped a humanitarian donor conference for Syria hosted in Kuwait this week would raise more than last year's $1.5 billion.

Speaking to Reuters during a visit to Syria ahead of the Wednesday meeting, Amos said the United Nations was looking for a total of $6.5 billion this year to help those suffering from the nearly three-year conflict.

Syria's war has killed over 100,000 people and forced more than 2 million to flee abroad, according to the UN. Another 4 million have been displaced inside the country.

Amos, who met with government officials and visited displaced Syrians, said the situation was getting worse.

"The numbers are going up significantly in terms of the numbers of people that we are needing to help here inside Syria, the number of people displaced," she told Reuters.

"I'm not sure when they will be able to go back home. Everyone is desperate to go home."

Amos said some 2.5 million people were in areas that were hard for aid workers to reach due to fighting and sieges by government or rebel forces.

"There are people in communities that we have not been able to get to at all, people in communities which are besieged either by the government forces or by opposition forces who have not been able to leave and where relief goods have not been able to go in," she said.

The $1.5 billion pledged via the UN at last year's Kuwait hosted conference was used in Syria and surrounding countries to provide food rations, medicine, drinking water and shelters.

"We hope we'll raise a little more this time," Amos said. "And we will of course continue our fundraising during the year."